Plant Nutrition

Title :

Plant Nutrition

Author :

Kim Foglia & Kelly Reidell

Number of slides:



Slideshow :

Content transcript :

Physiological adaptation
Nutritional needs
* Autotrophic does not 
mean autonomous
* plants need…
* sun as an energy source
* inorganic compounds 
as raw materials
* water (H2O)
* CO2
* minerals
* Plants require these nutrients in relatively large amounts
* C, O, H, N, P, K, Ca, Mg, S
For what & from where?
Local Long Island soil issues
* Plants require in very small amounts
* Cl, Fe, Mn, Bo, Zi, Ni, Mb
* primarily cofactors for enzyme function
Nutrient deficiencies
* Lack of essential nutrients 
* exhibit specific symptoms
* dependent on 
function of nutrient
* dependent on 
solubility of nutrient
Magnesium deficiency
* Symptoms
* chlorosis = yellowing of leaves
* Why? What is magnesium’s function?
The role of soils
* Plants are dependent on soil quality
* texture / structure
* relative amounts of various sizes of soil particles
* composition
* organic & inorganic chemical components
* fertility
Importance of organic matter
* Topsoil
* most important to plant growth
* rich in organic matter
* humus
* decomposing organic material 
* breakdown of dead organisms, feces, fallen leaves & other organic refuse by bacteria & fungi 
* improves soil texture
* reservoir of minerals
* organisms
* 1 tsp. of topsoil has ~5 billion bacteria 
living with fungi, algae, protists, insects, 
earthworms, nematodes
Soil health as a global issue
Not taking care of soil health has 
far-reaching, damaging 
* 1920’s Dust Bowl
* lack of soil conservation
* growing the same crop 
year after year (wheat)
* grazing by cattle
* bare ground exposed to 
wind erosion in winter
* drought
Soil health as a global issue
* Soil conservation & sustainable agriculture
* maintaining healthy environment
* sustainable production of food supply
* economically viable farming industry

Global Issues
* soil fertility
* erosion
* irrigation
* forestry destruction

* “Organic” fertilizers
* manure, compost, fishmeal
* “Chemical” fertilizers
* commercially manufactured
* N-P-K  (ex. 15-10-5)
* 15% nitrogen
* 10% phosphorus 
* 5% potassium
Nitrogen uptake
* Nitrates
* plants can only take up nitrate (NO3-)
* Nitrogen cycle by bacteria
* trace path of nitrogen fixation!
Soybean root nodules
* N fixation by Rhizobium bacteria
* symbiotic relationship with bean family (legumes)
Increasing soil fertility
* Cover crops
* growing a field of plants just to 
plow them under
* usually a legume crop
* taking care of soil’s health
* puts nitrogen back in soil
Some plant oddities…
Parasitic plants
* tap into host plant vascular system
Plants of peat bogs
* High acid environment
* most minerals & nutrients bound up & are not available to plants
* must find alternative sources of nutrients
Are they really carnivores?

Uses of peat
Any Questions??

0 التعليقات:

Post a Comment